From ac1c274b02cd48973553c83dd3a822fdddbfe5a7 Mon Sep 17 00:00:00 2001
From: kmyuhkyuk <72241714+kmyuhkyuk@users.noreply.github.com>
Date: Sun, 8 Mar 2026 23:27:41 +0800
Subject: [PATCH] Fixed IdCollision HandshakeResponse will not send Added
 ConnectToHost auto try NetID feature

---
 .../Components/IPAddressLineEdit.cs           | 22 +-----
 .../ENetClientConnectionInitializerPatch.cs   | 73 +++++++++++++++++++
 .../Patchs/ENetHostPatch.cs                   | 40 ++++++++++
 3 files changed, 115 insertions(+), 20 deletions(-)
 create mode 100644 SlayTheSpire2.LAN.Multiplayer/Patchs/ENetClientConnectionInitializerPatch.cs
 create mode 100644 SlayTheSpire2.LAN.Multiplayer/Patchs/ENetHostPatch.cs

diff --git a/SlayTheSpire2.LAN.Multiplayer/Components/IPAddressLineEdit.cs b/SlayTheSpire2.LAN.Multiplayer/Components/IPAddressLineEdit.cs
index d34b06e..e8db748 100644
--- a/SlayTheSpire2.LAN.Multiplayer/Components/IPAddressLineEdit.cs
+++ b/SlayTheSpire2.LAN.Multiplayer/Components/IPAddressLineEdit.cs
@@ -22,27 +22,9 @@ namespace SlayTheSpire2.LAN.Multiplayer.Components
 
         public bool IsIPAndPort => IPAndPortRegex().IsMatch(Text);
 
-        public string? IPAddress
-        {
-            get
-            {
-                if (IsOnlyIP)
-                    return Text;
+        public string? IPAddress => IsOnlyIP ? Text : IsIPAndPort ? Text.Split(':').First() : null;
 
-                return IsIPAndPort ? Text.Split(':').First() : null;
-            }
-        }
-
-        public ushort? Port
-        {
-            get
-            {
-                if (IsIPAndPort)
-                    return Convert.ToUInt16(Text.Split(':').Last());
-
-                return null;
-            }
-        }
+        public ushort? Port => IsIPAndPort ? Convert.ToUInt16(Text.Split(':').Last()) : null;
 
         public override void _Ready()
         {
diff --git a/SlayTheSpire2.LAN.Multiplayer/Patchs/ENetClientConnectionInitializerPatch.cs b/SlayTheSpire2.LAN.Multiplayer/Patchs/ENetClientConnectionInitializerPatch.cs
new file mode 100644
index 0000000..670fad5
--- /dev/null
+++ b/SlayTheSpire2.LAN.Multiplayer/Patchs/ENetClientConnectionInitializerPatch.cs
@@ -0,0 +1,73 @@
+using HarmonyLib;
+using MegaCrit.Sts2.Core.Entities.Multiplayer;
+using MegaCrit.Sts2.Core.Helpers;
+using MegaCrit.Sts2.Core.Logging;
+using MegaCrit.Sts2.Core.Multiplayer;
+using MegaCrit.Sts2.Core.Multiplayer.Connection;
+using MegaCrit.Sts2.Core.Multiplayer.Transport.ENet;
+using MegaCrit.Sts2.Core.Platform;
+
+// ReSharper disable UnusedMember.Global
+// ReSharper disable UnusedType.Global
+
+namespace SlayTheSpire2.LAN.Multiplayer.Patchs
+{
+    [HarmonyPatch(typeof(ENetClientConnectionInitializer), "Connect")]
+    internal class ENetClientConnectionInitializerPatch
+    {
+        private static bool Prefix(NetClientGameService gameService,
+            CancellationToken cancelToken, ulong ____netId, string ____ip, ushort ____port, ref Task __result)
+        {
+            __result = TaskHelper.RunSafely(Connect(gameService, cancelToken, ____netId, ____ip, ____port));
+
+            return false;
+        }
+
+        private static async Task<NetErrorInfo?> Connect(NetClientGameService gameService,
+            CancellationToken cancelToken, ulong netId, string ip, ushort port)
+        {
+            if (gameService.IsConnected)
+            {
+                throw new InvalidOperationException(
+                    "NetClientGameService must not be connected when passed to ENetClientConnectionInitializer!");
+            }
+
+            var eNetClient = new ENetClient(gameService);
+            gameService.Initialize(eNetClient, PlatformType.None);
+
+            var count = 0;
+            const int tryCount = 10;
+            NetErrorInfo? netErrorInfo = null;
+
+            while (count < tryCount)
+            {
+                if (cancelToken.IsCancellationRequested)
+                    return netErrorInfo;
+
+                netErrorInfo = await eNetClient.ConnectToHost(netId, ip, port, cancelToken);
+
+                if (!netErrorInfo.HasValue)
+                {
+                    Log.Info($"Connect {ip}:{port} Host Game NetID:{netId}");
+                    return null;
+                }
+
+                if (netErrorInfo.Value.GetReason() != NetError.Kicked)
+                    return netErrorInfo;
+
+                var nextNetId = netId + 1000u;
+
+                if (count < tryCount - 1)
+                {
+                    Log.Warn($"{ip}:{port} Host Game NetID:{netId} already occupied, next try NetID:{nextNetId}");
+                }
+
+                netId = nextNetId;
+
+                count++;
+            }
+
+            return netErrorInfo;
+        }
+    }
+}
\ No newline at end of file
diff --git a/SlayTheSpire2.LAN.Multiplayer/Patchs/ENetHostPatch.cs b/SlayTheSpire2.LAN.Multiplayer/Patchs/ENetHostPatch.cs
new file mode 100644
index 0000000..41a8028
--- /dev/null
+++ b/SlayTheSpire2.LAN.Multiplayer/Patchs/ENetHostPatch.cs
@@ -0,0 +1,40 @@
+using System.Reflection;
+using System.Reflection.Emit;
+using Godot;
+using HarmonyLib;
+using MegaCrit.Sts2.Core.Multiplayer.Transport.ENet;
+
+// ReSharper disable UnusedMember.Global
+// ReSharper disable UnusedType.Global
+
+namespace SlayTheSpire2.LAN.Multiplayer.Patchs
+{
+    [HarmonyPatch]
+    internal class ENetHostDoClientHandshakePatch
+    {
+        private static MethodInfo TargetMethod()
+        {
+            return AccessTools.AsyncMoveNext(typeof(ENetHost).GetMethod("DoClientHandshake",
+                BindingFlags.Instance | BindingFlags.NonPublic));
+        }
+
+        private static IEnumerable<CodeInstruction> Transpiler(IEnumerable<CodeInstruction> instructions)
+        {
+            //Fixed IdCollision HandshakeResponse will not send
+
+            var peerDisconnectMethod = AccessTools.Method(typeof(ENetPacketPeer), "PeerDisconnect");
+            var peerDisconnectLaterMethod = AccessTools.Method(typeof(ENetPacketPeer), "PeerDisconnectLater");
+
+            foreach (var instruction in instructions)
+            {
+                if (instruction.opcode == OpCodes.Callvirt && instruction.operand as MethodInfo == peerDisconnectMethod)
+                {
+                    yield return new CodeInstruction(OpCodes.Callvirt, peerDisconnectLaterMethod);
+                    continue;
+                }
+
+                yield return instruction;
+            }
+        }
+    }
+}
\ No newline at end of file